3 ton digger arm not lifting

raher1

A question relating to a 3 ton kubota digger. It's the old type with two handles to move the front arm. The problem is that front arm is not working with you try to move it. I have tried oil changes, filters and checked for air locking. Is there anything else I could do?

patsy_mccabe

Can you see the valve operating when you pull the lever? Can you feel pressure, like a slight kick, in the pipe when you operate it. Maybe pressure is still held on the opposite side of the ram.

raher1

Is that the bucket side? How do you check that pressure

148multi

Is any of the controls working, including the tracks

raher1

Only the tracks

RockOrBog

Is there a safety lever inside the door you lift and drop before you enter or exit. Sounds like a problem with that

148multi

Would your tracks normally work with the dead man switched off

The Nutty M

https://www.boards.ie/discussion/comment/122958121#Comment_122958121

Nope.

OP, you say no controls work at all from either of the two hand levers? No swing left or right at all? It's a weird one.

Was it working before and just stopped or what happened? Could be as simple as something in the linkages to the valve block not opening and closing the PCV's. Check and make sure when you pull the lever in the cab, you see the linkages moving at the valve chest.

A digger of that size I would think it would only have one pump and the fact it is tracking makes that one pump serviceable. Now if it has two pumps, I would be going looking at the input shaft to these pumps. Unfortunately it's a matter of working out if you have any pump pressure. From what you describe with two levers I assume it's a pioneer machine with no pilot pressure circuit. This makes it easier.

RockOrBog

https://www.boards.ie/discussion/comment/122959010#Comment_122959010

I've seen diggers where the tracks still move with the dead man up but the boom or dipper won't, including an old Volvo which I regularly drive. Id check the dead man switch

148multi

https://www.boards.ie/discussion/comment/122959340#Comment_122959340

Some diggers track with deadman off alright, but I don't know about this one. also don't know if it has a servo circuit.

older by the day

My old hitachi tracks with the safety lever up. So it's worth checking before going ripping

RockOrBog

https://www.boards.ie/discussion/comment/122959464#Comment_122959464

I don't think it has servos, sounds like old school hydraulics

rje66

Ccheck foot pedal for breaker isn't jammed or in some way engaged..…

raher1

I will do that.

The Nutty M

https://www.boards.ie/discussion/comment/122962147#Comment_122962147

Any update Raher? Did you manage to get it working?